Self and james doyle



@uiten gisten -gatrut ffirr.y

PATRICK CLIFFORD, 0F HOLYOKE, MASSACHUSETTS, ASSIGNOR TO lHIM- SELF AND JAMES DQYLE, OF SAME PLAGE.

Letters Patent No. 71,279, dated November Q6, 1867.

IMPROVEMENT IN ADJUSTABLE SPIRIT-LEVELS.

TO ALL WHQM IT MAY CON CERN:

Be itfknown that I, PATRICK CLIFFORD, of Holyoke, in the oountyiot Hampden, and Commonwealth of' Massachusetts, have invented certain new and useful Improvements in Adjustable Spirit-Levels; and I do hereby declare that the following is a full and exact description thereof, referencebcing had to the annexed drawings, making a part of this specification, and to the letters of reference marked thereon, in which- Figure 1 is a plan of said level. y

Figure 2 is a side elevation.

Figure 3 isv a bottom plan of the level-case.

Figure 4 is an end elevation of said level;

Figure 5 is a transverse vertical section of the index-plate g through line D E, iig. 2.

The nature of my invention relates to certain improvements in adjustable spirit-levels, of the construction described in Letters Patent, granted to me for improvement in combined level and plumb, No. 65,726, and dated June 11, 1867, in which a spirit-level, mounted ina small metallic case, is attached to a stock of metal or wood in s uch a manner that the said stock, having the level so attached, may be used as a level, a plumb, or for ascertaining the angles lformed by the lines of any surface with the horizon.

My said 4improvements consist in attaching a graduated semicircular indexplate to thespindle on which the level-cascturns; and iu certain devices, by means of which the index-plate is retained in any certain position; and also in the construction of an adjusting-pin and screw, and appartenant parts, by which the indexplate' may be correctly set upon the spindle, if accidentally misplaced, or by which the accuracy of its adjustment may be tested at any time. i

The construction of my invention is as follows: The stock consists of the straight face-plate A, of suitable length and width, and a flange, B, set at a right angle to A, and of curved outline, as shown. The stock may beconstructed of inetal or wood, according to the purpose for which it is to be used. The tube or bubble ofthe spirit-level is enclosed in a metallic case, F, and secured by the slotted plate c,the slot in which permits an inspection ofthe glass tube.` A circular shoulder, e, is cast upon the side of the case F, of the same diameter as the shouldersf and z on the fiange B of th'e stock. A spindle, u, projects at a right angle from the shoulder e, and is made slightly conical for a portion of its length to u', and the remainder is turned of smaller diameter and a male-screw thread cut upon it. To strengthen the support of the shoulder and spindle, the curved proa jection t is'cast upon the bottom ofthe level-elise. The spindle it turns in a bearing in B., Y

As' it is desirable to retain the level-case in any particular position in which it may have been adjusted, I substitute for the index, described in my before-granted Letters Patent, a graduated index-plate, y, and retain it in any desired position in its revolution by means of the spring detcnt 7c, which is fastened to the stock by the screw t', and depressed by thc thumb-piece 7c. The outer edge of this ,index-plate is circular from o to'o, and the central circular opening is made slightly daring or conical to'tit closely upon the spindle et, and t-urn with it, whenever the plate is forced tightly on the spindle, by turning the nut Z. The shoulder m m (fig. 5) is projected from the index-plate g, as a bearing for the-nut Z, andthe edge of the 1111i? is mined t enable the operator t0 grasp it iirmly in turning it.. rIhc'edge of the index-plate is indented by the angular notches 10p placed closely together in regular order. To insure accuracy of adjustment, all the notches upon the edge of the indexplate are made precisely alike, and the tooth :e in the detent 7e is made to exactly fit these angular notches, so that the level-case is brought to the same exact position whenever thetooth :c enters the same notch in the edge of the plate. I consider thel angular form of the notches 1J p, and the'corresponding shape of the tooth a: to be a valuable adjunct to this form of level for insuring accuracy. lt willbve seen that the indexplate is graduated in degrees; but any suitable graduation may be adopted .which is applicable to the purpose of the operator, such as a scale for determining the'batter of walls and cmbankments, oreny other necessary scales. l

As the index-plate may souictimesbecomc loosened or misplaced in the, spindle, I employ the followingdescribed construction, which enables the operator to rcadjust the index-plate on thefspindle, or to testuthe accuracy of its adjustment. '.lhc two projections s s are cast upon the bottom of the level-case F, and an adjusting-pin, .a, is inserted in bearings formed in s s', being thrust. forward or drawn beck by a head nt the end. A small pin, r, limits the traverse of the adjusting-pin a. Upon the ilange B of the stock is a projection, d, in which is a seat for the screw b. The index-plate is to be set upon the conical spindle in such a position that the bubble indicates correctly a level position of the face ofthe stock when the tooth a; enters the angular notch immediately beneath 0, and the indexsplate is then forced tightly upon the spindle by turning up the nut Z. New, when the level-case and the tooth :c are in the position described, if the screw l: be turned upward or downward until the adjusting-pin a rests upon the head of the screw, the operator will-have n. ready means of adjusting the position of the index-plate on the spindle, or of testing` its adjustment at any time. i The head of the screw b is, for the time being, u fixed point, and will be likely to remain at the same elevation, while the index-plate is more liable to become misplaced on thc spindle. When the pin a is not in use for adjustment, it is drawn back to the position shown by the red lines, lig. 4, and does not then interfere with the movement of the level-case on the spindle. I do not confine myself to the particulauform and construction of the stock A B, as any form of stock, which will afford a. proper support for the spindle u, and for the adjusting-,screw b, may be used.

What I claim as new, and desire to secure by Letters Patent, is

1. The graduated index-plate y, having the angular notchespp, and central conical opening g', in combi nation with the tapering spindle u and spring detent k, the whole arranged and operating substantially as set forth. v

2. The adjusting-pin a and screw b, in combination with the revolving level-case F and stock A B, substan tally as described.

PATRICK CLIFFORD.

Witness es z C. BLODAGETT, DONALD MAcKrNTosn; 

